Detective Conan Manga by Aoyama Goushou

High school detective Kudo Shinichi is infamously known to the people of Japan as "The Modern Sherlock Holmes". Yet things will detective.conand as he is drugged by two mysterious men in black and found himself shruken to the size of a kid. Hiding his real name, Shinichi now lives with his childhood sweetheart Mouri Ran under the name of Edogawa Conan and hoping to find some clues about the men in black through clients and cases of Ran's father - a pathetic second-class detective who quickly became well-known through secretive helps from Conan.